Claude Fit Logger has clear, verb-based tool names and reasonable descriptions (avg 180 chars), but parameter documentation is inconsistent and output schemas are not formally documented. All four tools have input schemas with types, but descriptions lack actionable constraints (e.g., timezone format, calorie range). The log_food tool's multi-step fallback pattern is well-explained but adds cognitive load. Error responses are generic (status codes without recovery guidance). No tool annotations (readOnlyHint, destructiveHint) despite clear risk profiles.

• Add tool annotations: @mcp.tool with destructiveHint=True for undo_entry and remove_entry; readOnlyHint=True for get_totals. This signals agent safety policies and prevents accidental misuse.
• Document output schemas explicitly. For log_food, specify: {status: 'logged'|'not_found', entry_id?: int, nutrients: {calories: float, protein_g: float, ...}, today_totals: {calories: float, ...}, entries: [{item_name: str, ...}]}.
• Add numeric constraints to parameter descriptions: 'quantity_g: positive number (0.1 - 10000)', 'calories: positive number (0 - 5000) when provided'. Include timezone validation hint: 'Must be a valid IANA timezone (e.g., America/Toronto, Europe/London)'.
• Enhance error responses with recovery hints. E.g., if Google Health write fails: {status: 'error', message: 'Failed to write to Google Health. Retry with get_totals() to verify state, then log_food() again if needed.'}.
• Add idempotency key support to log_food: accept optional idempotency_key parameter so retries don't create duplicates. Document: 'If provided, same key + item_name + quantity_g + tz will return cached result instead of creating a new entry.'

Inferred effective spec: <=2025-11-25.

• Relies on Dynamic Client Registration (deprecated) - use Client ID Metadata Documents (CIMD)